Photohectographic duplicating



May 4, 1965 D. A. NEWMAN 3,181,462

PHOTOHECTOGRAPHIC DUELICATING Filed Feb. 2'?, 1961 mvENToR. D@ :ffylaf A. Mea/maf@ United States Patent G 3,181,462 PHQTGHECTOGRAPHIC DUPLICATING Douglas A. Newman, Glen Cove, NX., assigner to Columbia Ribbon and Carbon Manufacturing C0., Inc.,

Glen Cove, NX., a 4corporation of New York Filed Feb. 27, 1961, Ser. No. 91,699 4 Claims. (Cl. 1in-149.4)

This invention relates to duplicating and especially to preparation of duplicating images by photographic methods whereby exact reproductions of given original mate- -rial can be brought about, and is a continuation-in-part of application Serial No. 420,123, tiled March 31, 1954, now abandoned.

Heretofore the use of duplication methods involving the production of a photographic image for exact copy purposes, or for other reasons, has made it necessary to produce the final copies by means which are inherently expensive, thus limiting the usefulness of the system. For example, if a complete photographic system is used, the copies are made using relatively costly paper sheets having a photographic emulsion on their surfaces, or if the printing image is prepared as a photosensitized planographic printing plate, it is essential that a suitable press be available to make the desired copies.

The present invention is directed towards avoiding the costly features of such processes as those indicated above and is accordingly based on preparing an image for hectograph duplication using a photographic exposure in the initial preparation of the image. For convenience, in the `following description, processes having this basis of operation will be referred to as photohectographic processes and this expression will be understood to have this significance wherever it appears hereinafter.

While certain photohectographic reproduction methods have been known heretofore, these have required the handling of free dyestuif in powder or solution form for treating a photographically formed image to make of it a hectographic master, thus rendering them unt for general oiiice use. tion, therefore, to provide a photohectographic method for duplicating which permits the formation of the master image by photographic means, but which is at the same time inexpensive enough to permit Widespread use, and simple and clean enough for systems use in ordinary otiice practice, together with the novel sheets and equipment for carrying out such a method.

Other features and advantages will hereinafter appear.

In the drawing:

FIGURE l is a diagrammatic section, on a large scale,

exposure and initial processing to make one form of master.

FIG. 2 is a view similar to FIG. l showing the sheet of FIG. l together with an auxiliary sheet and illustrating a step in the process of preparing another form of master.

FIGS. 3 and 4 are views similar to FIG. 2 but illustrating sheets and steps in a slightly ditierent process of preparing a master.

The present invention is susceptible of being carried out in a plurality of ditierent ways and using sheets of slightly different forms. Several of these have been illustrated in the accompanying drawings and will now be described in detail with reference thereto.

In FIGS. l and 2 is illustrated a photohectograph process which employs a positive original. A specially prepared sheet A is shown in FIG. l against which the original may be placed or projected for exposure. The

It is an object of the present invenll Patented May 4, i965 sheet A consists of a paper or other suitable flexible foundation 13, a hectographic coating 14 on one surface of the foundation 13 and a photosensitive coating 1S overlying and covering the coating 14. The coating 14 includes a large proportion of soluble dye which may be carried in any suitable hlm-former or binder for application purposes. As an example, the coating 14 may be formed of methyl violet supported in a layer of wax as in a conventional hectographic transfer sheet. The photosensitive layer 15 may comprise any conventional light-sensitive hydrophilic organic colloid layer such as bichromated gelatin or albumin, polyvinyl alcohol-diazo layer, gelatino-silver halide layer or the like. As desired, the corresponding conventional developing and hardening or tanning agents may be incorporated into the photosensitive layer or applied in a subsequent operation.

When the sheet A has been exposed to light through the positive original, the areas of its surface covered by the dark or image areas will be protected from exposure while the background areas will receive the light. Thereafter the exposed photosensitive layer is conventionally developed and tanned or hardened in the exposed areas while the uncxposed areas remain unaffected. As seen in FIG. l, an image area is formed at the location indicated by the reference character 16 where the unhardened unexposed portion of the photoresponsive layer 15 has been removed physically or by a subsequent Washing treatment and the background areas remain in place in the form ot the developed and hardened or tanned portion of the photoresponsive layer 15.

A completed sheet A as shown in FIG. l may be used as a master in either the spirit process or the gelatin process of hectograph duplication, depending upon whether the image used was so placed as to give a mirrorreverse or direct-reading image on the sheet A. Placing of the images may be controlled by positioning the original so that the images thereon face either the light source or the photosensitive layer, or by using a directreading or reverse-reading original as desired.

In the case of the spirit process the sheet A will be reverse-imaged and brought into contact wit-h a series of copy sheets each moistened with spirit fluid, and a small portion tot dye from the image area 16 Will be picked up by each moistened sheet to give a direct-reading copy. The hardened photo layer 15 prevents lany pick-up of dye from the background areas. 4If the gelatin method is used, the gelatin hectograph mass or blanket is moistened wit-h :water and the direct-reading sheet A is pressed -thereagai-nst. A substantial portion of the dye in the image areas 16 goes over to the moistened gelatin as reverse images, while the background areas are protected against `the dye by the hardened or tanned portions of layer 15. From the moistened hectograph blanket, direct-reading copies can be taken by pressure in the wellknown manner.

It is preferred, however, to use the sheet A as an intermediate for forming the master, and this process is illustrated in FIG. 2 wherein the master sheet B consisting of a paper found-ation 17 and a coating 18 is pressed against 'the surface of the sheet A. 'Ille coating 1S isv either normally slightly tacky, or Iis of material `which` `can Ibe rendered temporarily slightly tacky by any suit-- able treatment, and when the sheets A and B are pressedtogether the tacky surface of the coating 18 picks up a; portion ot the hectographic coating 14 of the sheet A inthose image areas 16 Where it is exposed by the removal.' of the unhardened pontion-s of the p-liotosensitive layer, thus forming an image 19. The hardened portion of photoresponsive layer 15 on sheet A is unaffected by thev 14 in the background areas. Sheet B, ater being imaged in this manner, may be used as the master sheet in either la spirit or gelatin process of hectographic reproduction in the same Way as described for sheet A. The original, however, willi haverto be arranged so as to be exposed in a direction the reverse of that u'sed when sheet A is to be the master.

'In the form of the invention described immediately above, IWith respect -to FIG. 2, ltiene master sheet B Was set out as being provided with an adhesive coating 18. This coating is no tI necessary to the operation in all cases, however, for the unhardened portions 15a of the lightsensitive hydrophilic organic colloid layer 15 in many cases have an adhesive property suicient to make any special adhesive layer unnecessary, as illustrated by FIG.. 3 .In ya case of this sort, thesheet A, after exposure, would be moistened on` its Working surface. This moistening treatment results in a subtantial increase in the tackiness of the unhardened portions 15a of coating 15 coveringV the image areas, and in little or no such increase in .the hardened background' areas. When 4an ordinary paper master sheet 17 takin-g the place of the master sheet B ofF'IG. 2V is pressed against this moist surface, it adlheres to the tacky portions 15a of coating 15 in the image areas only. When the sheets are separated, these tacky portions are lifted Ifree of the sheet A carrying .with them substantial portions 14a of the underlying coating 14, thus forming iheotograiphic image areas', a-s shown by FIG. 4. When a master sheet'formed in this manner has been driedto set the adhesive port-ions 15a of the phot-osensitive layer, it ijs ready to be used in either thev spi-rit or gelatin process in exactly the same manner as the master sheet B. v

While* the hectograph layer 14 has been characterized v as being the conventional,pressure-sensitive transfer layer as used on hectograph carbom it Will be understood that slight variations may be made in the composition thereof, it desired, in order to. improve the temperature sensitivity and solubility of the. layer 'and improve the properties of the same for a heat-release :type of opera-tion. The heat sensitivity of the hectograph transfer layer may be controlled by employing therein higher or lower melting point waxes as desired; Heat resistant cellulose binders may be employed, such materials being disclosed in my lcopending application Serial No. 852,612, filed November 13, 1959 now U.S. Patent No. 3,054,692, issued September 178,. 1962. The hectograph transfer layer may contain any conventional hectograph dyestuff such as those of the triaryhnethane, rhodamine and safranine rfa-milies including crystal Violet, methyl violet, magenta, Victoria green or the like. However, it is preferred, in carrying out the embodiment shown by FIG. l Where removal of the unexposed portions of the photosensitive layer isy accompli-shed by Washing, that the dyestuff used in layer 14 is one which is insoluble in the washing liquid such as'water. In place of conventional hectograph dyestuffs, hectogra-ph layer 14 may contain Vsubstantially colorless complementary chemicals or dyestul components which rea'ct to form colored images on specially :treatedV copy sheets as taught by U.S. -Patents Nos. 2,634,677 and 2,872,863.

The composition of tacky layer 18 herein employed rnay be varied Widely depending upon the intended end use of the sheet bearing the tacky layer. Materials may be used which are normally tacky or adhesive, although it is preferable that `layer 18` comprise a composition Which is normally substantially non-tacky and non-adhesive but which canbe-rendered temporarily tacky and adhesive by a suitable treatment such as by the application of heat or a volatile solvent or the vapor thereof.

Preferred for this purpose are thermoplastic resinons materials and mixtures thereof` with waxes. Suitable resinous materials include halogenated hydrocarbon polymers such as lthe Arochlor resins; cellulosic materials sil-91.1.35 ethyl cellulose; polyterpene reins such as Piccolyte and Nypene; unsaturated hydrocarbon polymers such as the polyisobutylenes (Vistanex and Indopol); acrylate and methacrylate polymers such as polymethyl acrylate and poly-n-butyi methacrylate; plasticized polyvinyl chloride and acetate; the vinyl alkyl ethers such as Oppanol C which is vinyl-n-butyl ether; and the various natural resins Such as abietic acid and its esters, -gum daminar, copal, Vinsol, coumarone-indene resin, hydro-genated rosin (Staybelite) and the like.

Preferred waxes for use in admixture with any of the foregoing resins include beeswax, microcrystalline Wax, candelilla wax, paraffin, and the like.

The physical properties of tacky layer 18 may be adj usted to suit the particular purpose which the layer is to serve or to suit the particular means by which it is to be activated and rendered tacky and adhesive. If heat is to be used as the activating force while the hectograpn transfer sheet and the tacky layer are in contact, then the composition of layer 18 should have the property of melting or becoming adhesive at a temperature lower than the melting temperature of either the dye-containing hectograph transfer layer or the photosensitive layer used therewith, preferably from about to 140 F.

lf a volatile solvent or the vapor thereof is to be used as the activating force While the hectograph transfer sheet and the tacky layer are in contact, then the composition of layer 18 should be at least partially soluble in a volatile organic solvent which is substantially a non-solvent for either the photosensitive layer or the dyestuff of the hectograph transfer layer. Suitable solvents include carbon tetrachloride, perchloroethylene, toluol, aliphatic ketones, etc.

VThe composition of the photosensitive or light-sensitive layer is not critical and the present invention contemplates the use of conventional photosensitive layers. Particularly preferred are those light-sensitive hydrophilic organic colloid layers of the type used in the preparation of photosensitive planographic printing plates. Suitable light-sensitive compositions and the developers and hardeners therefor include bichromated gelatin or albumin systems as disclosed in my U.S.v Patent No. 2,570,262; polyvinyl alcoholor other hydrophilic colloid-diazo layer systems such as disclosed in U.S. Patent 2,772,974; gelatin-silver halide layer systems as disclosed in U.S. Patents Nos. 2,312,852 and 2,596,756.

The developing and hardening or tanning agents for the photosensitive layer may be incorporated into the photosensitive layer at the outset so that the layer is selfdeveloping and self-insolubilizing upon being treated with an alkaline solution as disclosed in U.S. Patents Nos. 2,592,368 and 2,596,756, or the developing and hardening of the photosensitive layer may take place as an aftertreatment of the exposed layer to conventional developing and tanning or hardening agents as disclosed in U.S. Patents Nos. 2,596,756 and 2,570,262.

The following examples are merely by way of illustration and should not be construed as being limitative Exam ple 1 A conventional wax base hectograph transfer sheet containing aV crystal violet dyestuif-wax base transfer layer is coated on said transfer layer with a light-sensitive hydrophilic organic colloid composition contaning the following ingredients:

Ingredient: Parts by weight Gelatin 20 Silver nitrate 9 Sodium chloride 4 Water 3,4-dihydroxy diphenylV (developer) 3- Formaldehyde (hardening agent) 0.5

The coated sheet is dried to evaporate the Water and form the light-sensitive layer. Next an original sheet comprising a clear plastic film having black typed images oneness thereon is placed face down upon the light-sensitive layer so that the images are in surface contact with the light-sensitive layer, and the superposed sheets are subjected to a bright light source directed onto the back of the original. The sheets are then separated and the lightsensitive sheet is placed in an alkaline bath of sodium hydroxide to cause the exposed portions of the lightsensitive layer to become developed and hardened while the unexposed portions corresponding to the imaged areas of the original remain unhardened. The unhardened areas are then Washed away in a conventional manner to produce a duplicating master sheet of the type shown by FIG. 1 in Which the open areas lo define reverse-reading master images.

Spirit copies are produced from this master sheet in conventional manner by contacting the master with alcohol-moistened copy sheets which dissolve available dyestuff from areas lo to form direct-reading spirit copies.

Example 2 Where it is desired to produce a duplicating master sheet on conventional master paper, then the embodiment of FIG. 2 of the drawing may be carried out using the dye-containing sheet produced according to Example 1 above as sheet A and using as sheet B a conventional master paper having an adhesive surface layer of the following composition.

Ingredient: Parts by weight Beeswax Rosin 2 Indopol H-300 1 Sheets A and B are placed in surface contact and a uniform pressure is applied to insure complete overall adherence of the adhesive layer to the entire surface of sheet A. Upon separation of the sheets, the hardened areas of layer l5 remain on sheet A while the frangible layer 14 transfers to sheet B as portions 19 which were exposed through open image areas 15 as shown by FIG. 2 of the drawing.

Example 3 A light-sensitive layer was applied to the hectograph transfer layer of a conventional hectograph tranfer sheet and exposed to light through an imaged original sheet in the manner outlined in Example 1. After developing and tanning or hardening of the exposed portions of the lightsensitive layer, it is contacted with the surface of a sheet of master paper and a slight pressure is applied whereby the unhardened unexposed portions of the light-sensitive layer, due to their adhesive properties, bond to the master paper. Upon separation of the sheets, the unhardened portions 15:1 of layer 15 transfer to the master paper and carry with them portions 14a of the corresponding underlying hectograph layer 14 to form a dye-imaged duplicating master as shown by FIGS. 3 and 4 of the drawing.

ln the foregoing disclosure and the subioined claims, reference is made to hectographic processes, images, coatings, transfer sheets and the like. It will be understood that where this expression appears it is used in its ordinary sense of a process in which a plurality of copies are taken from a master image which includes a quantity of a soluble dye, by dissolving a little of the dye from the image and transferring the same to each copy sheet while the copy sheet and image are in contact. Images, coatings and transfer sheets of hectographic nature are, of course, those whose makeup includes suitable soluble dyes in releasable condition and in the usual proportions su'icient to provide a significant number of bright copies when called upon to do so.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

l claim:

1. The process of producing a hectograph master sheet directly from an imaged original sheet which comprises the steps of positioning said original sheet together with a sheet comprising a liexible foundation having on one surface thereof a layer containing undissolved hectograph imaging material carried by a binder material, and having on the surface of said layer a top protective photosensitive layer; exposing said photosensitive layer to light through said imaged original and hardening only the background areas; removing the unhardened areas of said layer to expose said layer containing hectograph imaging material in areas corresponding to the imaged areas of said original sheet; contacting said layer with a master sheet having a Working surface coated with an adhesive material, said adhesive material and said layer containing hectograph imaging material making contact at said exposed areas; and separating said sheets causing portions of said layer containing hectograph imaging material to transfer to the surface of said adhesive material in said image areas to form said hectograph master sheet.

2. The process of producing a hectograph master sheet directly from an imaged original sheet which comprises the steps of positioning said original sheet together with a photosensitive sheet comprising a flexible foundation having on one surface thereof a hectograph layer containing undissolved hectograph imaging material carried by a binder material, and having on the surface of said layer a top protective photosensitive layer of material capable of being hardened by exposure to light and remaining unhardened and removable substantially independently of said hectograph layer in areas where not exposed to light; exposing the photosensitive layer to light through said imaged original and hardening only the background areas; and removing only the photosensitive layer in the unexposed areas corresponding to the location of the images on the original sheet to form said hectograph master sheet.

3. The process according to claim 2 in which removal of the photosensitive layer in the unexposed areas is effected by washing away the unexposed portions of the photosensitive layer.

4. The process of producing a hectograph master sheet directly from an imaged original sheet which comprises the steps of positioning said original sheet together with a photosensitive sheet comprising a flexible foundation haviny on one surface thereof a hectograph layer containing undissolved hectograph imaging material carried by a binder material, and having on the surface of said layer a top protective photosensitive layer of material capable of being hardened by exposure to light and remaining unhardened and removable together with the underlying areas of the hectograph layer in areas Where not exposed to light; exposing the photosensitive layer to light through said imaged original and hardening only the background areas; moistening the unexposed areas to render them tacky and then pressing them against a master sheet whereby they adhere thereto; and separating said sheets whereby the moistened tacky areas remain adhered to and transfer to the master sheet carrying with them portions of the underlying hectograph layer to convert said master sheet to a hectograph master sheet.

References Cited by the Examiner UNITED STATES PATENTS 2,012,526 8/35 Whitmore lOl-149.5 X 2,634,677 4/53 Klirnkowski et al. lOl-149.4 2,824,600 2/58 Eckhardt 10i-128.3 X

DAViD KLEIN, Primary Examiner.

ROBERT A. LElGHEY, WILLIAM B. PENN,

Examiners. 

1. THE PROCESS OF PRODUCING A HECTOGRAPH MASTER SHEET DIRECTLY FROM AN IMAGED ORIGINAL SHEET WHICH COMPRISES THE STEPS OF POSITIONING SAID ORIGINAL SHEET TOGETHER WITH A SHEET COMPRISING A FLEXIBLE FOUNDATION HAVING ON ONE SURFACE THEREOF A LAYER CONTAINNG UNDISSOLVED HECTOGRAPH IMAGING MATERIAL CARRIED BY A BINDER MATERIAL, AND HAVING ON THE SURFACE OF SAID LAYER A TOP PROTECTIVE PHOTOSENSITIVE LAYER; EXPOSING SAID PHOTOSENSITIVE LAYER TO LIGHTD THROUGH SAID IMAGED ORIGINAL AND HARDENING ONLY THE BACKGROUND AREAS; REMOVING THE UNHARDENED AREAS OF SAID LAYER TO EXPOSE SAID LAYER CONTAINING HECTOGRAPH IMAGING MATERIAL IN AREAS CORRESPONDING TO THE IMAGED AREAS OF SAID ORIGINAL SHEET; CONTACTING SAID LAYER WITH A MASTER SHEET HAVING A WORKING SURFACE COATED WITH AN ADHESIVE MATERIAL, SAID ADHESIVE MATERIAL AND SAID LAYER CONTAINING HECTOGRAPH IMAGING MATERIAL MAKING CONTACT AT SAID EXPOSED AREAS; AND SEPARATING SAID SHEETS CAUSING PORTIONS OF SAID LAYER CONTAINING HECTOGRAPH IMAGING MATERIAL TO TRANSFER TO THE SURFACE OF SAID ADHESIVE MATERIAL IN SAID IMAGE AREAS TO FORM SAID HECTOGRAPH MASTER SHEET. 